Many people have used SkyAuction, us included. We will be staying a week this summer on a SkyAuction win. If you plan it right and win the the auction you want you can get some great deals.
We got a 2 bedroom unit this summer at Fairfield Orlando at Cypress Palms for $326 total after bid/tax/svc fee. Last year we stayed at Vacation Village at Parkway through a skyauction win and loved it. We were looking for it again this year but that property just has not showed up very often the past month or two.
Try and stay away from the bid per night auctions. Sometimes you can get an ok deal with them but quite often they end up costing more then you may be able to book through places like hotelkingdom or even direct.
Just make sure you read the conditions of the auction as some resorts may have a surcharge for certain seasons/dates.
There have been some auctions lately that will require you to attend a sales presentation but it will be stated in the auction. Most auctions do not require you to attend the presentation but some resorts will still try and get you to attend. You are not required to attend so if they ask you to a free breakfast or maintenance meeting, simply decline.